/*
 * Tencent is pleased to support the open source community by making
 * WCDB available.
 *
 * Copyright (C) 2017 THL A29 Limited, a Tencent company.
 * All rights reserved.
 *
 * Licensed under the BSD 3-Clause License (the "License"); you may not use
 * this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 *       https://opensource.org/licenses/BSD-3-Clause
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import Foundation

final class Counter {
    static let counter = Atomic<Int>(0)

    static func step() -> Int {
        return ++counter
    }
}

final class Tagged<Value>: Equatable {
    let identifier: Int
    let value: Value

    init(_ value: Value) {
        self.value = value
        self.identifier = Counter.step()
    }

    static func == (lhs: Tagged, rhs: Tagged) -> Bool {
        return lhs.identifier == rhs.identifier
    }
}
